CMV retinitis is the most common intraocular infection in patients w/AIDS. Over time, untreated CMV retinitis will destroy the retina. Prompt treatment of CMV retinitis involving the posterior pole is required to limit vision loss & blindness. Two drugs have been licensed by the FDA for treatment of CMV retinitis. Unfortunately, progression ultimately ensues despite use of either agent. HPMPC is a nucleotide analog w/potent activity against a broad spectrum of herpes virus, including those which cause disease in humans.